Answer:
a) the common difference is 20
b) 
c) the common difference is -13
d) 
Step-by-step explanation:
a) what is the common difference of the sequence xn
Looking at the table, we get x_3=16, x_4=36 and x_5= 56
Deterring the common difference by subtracting x_4 from x_3 we get
36-16 =20
So, the common difference is 20
b) what is x_8? what is x_12
The formula used is: 
We know common difference d= 20, we need to find 
Using
we can find 

So, We have 
Now finding 

So, 
Now finding 

So, 
c) what is the common difference of the sequence 
Looking at the table, we get a_7=104, a_8=91 and a_9= 78
Deterring the common difference by subtracting a_7 from a_8 we get
91-104 =-13
So, the common difference is -13
d) what is a_12? what is a_15?
The formula used is: 
We know common difference d= -13, we need to find 
Using
we can find 

So, We have 
Now finding
, put n=12

So, 
Now finding
, put n=15

So, 
Answer:
6/5
Step-by-step explanation:
Answer:
12/20
Step-by-step explanation:
Answer:
12.52 in.
Step-by-step explanation:
Area of square(A)=157in^2
length of square (l)=?
we know,
A=l^2
or,sqrt 157=l
12.52 in=l
Answer:
Alana is 13 years old.
Step-by-step explanation:
Assuming you meant Mazo = Maisel,
You start from the bottom:
Amelia is 10 years younger than 17-year-old Maisel.
Amelia is 7 years old. (17-10)
Ernie is 2 years older than 7-year-old Amelia.
Ernie is 9. (2+7)
Alana is 4 years older than 9-year-old Ernie.
Alana is 13 years old. (4+9)
Hope this helps!
-EmV